Why did the Soviet state degenerate into the monstrous bureaucratic regime of Stalin? Leon Trotsky analyzes how it came about, the Soviet state as it was in in the 1930s, the potential for genuine socialism hinted at by the advances of the USSR in spite of the bureaucracy, and what the tasks of the Marxists were in relation to it. He predicts in advance that if a political revolution did not succeed in overthrowing the bureaucratic regime and replacing it with workers' democracy, that capitalism would eventually be restored, with tragic consequences for the Soviet and world working class.